Automatic firearm with fixed barrel and breech-action.



` K. A. BRUNING. AUTOMATIC IIREABM WITH FIXED BARREL AND BRBEGH ACTION.

APPLIGATION FILED NOV. 17, 1911.

Patented Mar. 19

K. A. -BRUNING- AUTOMATIC EIREARM' WITH FIXED BARREL AND BREECH ACTION.

APPLICATION FILED 11017.17, 1911.

l1,020,596, l Patented Mar. 19, 191.2. A

3 SHEETS-SHEET 2.

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v K. A. BRUNING. AUTOMATIC PIRBARM WITH FIXED BARREL ANDV BREEOH ACTION.

APPLICATION FILED NOV. 17, 1911. v

Patented Mar. 19, 1912.

3 SHEETS-SHEET 3.

ll|||||| III- KARL AUGUST BRUNING, OF HERSTAL, NEAR LIEGE, BELGIUM.

AUTOMATIC FIREARM WITH FIXED BARRELAND BREECH-ACTION.

Specification of Letters Patent.

Patented Mar. 19, 1912.

Application led November 17, 1911. Serial No. 660,891.

To all whom t may concern.'

Be itknown that I, KARL AUGUST BRUN ING, engineer, a` subject of theEmperor of Germany, and resident of Herstal, near Liege, in the Kingdomof Belgium, have invented certain new and useful Improvements inAutomatic Firearms with 'Fixed Barrels and Breecli-Actions; and I dohereby declare the followinor t0 be a full, clear, and exact descriptionof the invention, such as will enable others skilled in the art to whichit appertains to make and use the same, reference being had to theaccompanying drawings,.and to letters or figures of reference markedtherein, which form a part of'this specification.

The present invention relates to an automatic fire-arm with fixed barreland breechaction, in which the breech-action is controlledby a lockrotating in the movable breech.

The motion of the lock is Obtained by the displacing of the firing-pinunderthe action of gas pressure. In the forms of construction hererepresented, the action of the gases is transmitted t0 the firing-pin bya piston guided in an opening in the movable breech.

The fire-arm can be employed Wlth ordinary cartridges (Figure 11) orwith special cartridges having a hole in the back end of the shell(Figs. 1 to 10). U

In the drawings showing the inventlon as applied with special cartridgesFig. 1 is a vertical longitudinal section of the breech with ,thetiring-pin in the posit-ion after tiring. Fig. 2 is verticallongitudinal section ot' the breech with the tiring-pin in the positionready for firing. Fig. 3 is a vertical longitudinal section of thebreech 4With the firing-pin in the unlocking position. Fig. 4. is avertical transverse section of the rotating lock in the lockingposition. Fig. 5 is a .vertical transverse section of the rotating lockin the unlocking position. Fig. 6 represents the firing-pin and the searin side and end view. Fig. 7 is a side View partly in section of thecartridge with the small hole in its back-end. Fig. 8 is a side and anend View of the movable breech. Fig. 9 is a side View, a plan'view. andtwo end views of the rotating lock. Fig.Y l0 is a detail of the pistonand of the lock. Fig. ll is a view similar to Fig. 2 showing amodication.

After the delagration of the cartridgein the barrel. a part ot' thegases pass through a small opening R1' in the cartridge-shell R (Fig. 7)to the back of this shell and thence, for an;7 position of thecartridge, through the annular groove A1 andthe passage AL into -theopening of the breech bolt A. in which slides the piston B. By the highpressure of the gases the cartridge shell and its back-end are pressedagainst the fore-end of the breech bolt, thus producing a tight closingto the exterior. The piston B is provided at its fore-end with abrass-pieceB1 by which the tightness is insured under the pressure ofthe gases, so that no gas can leak out to the 'back through the openingA3. The pressure of the gases pushes backward the piston B and at thesame time the firing-pin C which bears with its jaw C1 against theback-end of the piston B. The rotating-lock E is forced to rotate lduring this backward movement of the firing-pin C thus causing theunlocking. The

.rotating-lock E is placed in a chamber A4 of the breech-bolt and iscentered by the cylindrical part of the firing-pin C. A stud C2- of thefiring-pin C, .which cannot rotate, extends downwardl and slides in acurved guide E1, E2, E' of the rotating lock. The rectilinear fore-partE3 of this curved guide of the rotating lock corresponds to the lockingposition (Fig. 4) of the lock, which it occupies during the recoil ofthe firing-pin in the position forfiring (Fig. 2), z'. e., as long asthe sear D presses With its notch D2 against the `salient piece A5 ofthe bolt A. By continuing its backward movement the firing-pin reachesthe position Fig. 3,

'l'. c. when the fore-notch D1 of the sear D reaches the salient pieceA5. During this movement of recoilof the firing-pin C the stud C2 entersthe oblique part E2 of the curved guide of the lock which is forced to]rotate and thus to unlock the breech bolt (Fig. 5). The unlocked breechbolt is compelled to follow the pieces already in motion and the breechis completely unlocked. The empty cartridge-shell is thenejected in theusual way; a new cartridge comes up from the magazine to the front ofthe breech bolt, which when pushed forward by the closingspring Kintroduces the new cartridge into the barrel.

when the. breech bult, in as initial for-v to the sear D and frees thefiring-pin C until by a short movement, the notch D2 of the Sear reachesthe salient piece A5. The short movement of the firing-pin C issufficient to allow the stud C2 `to slide through the oblique part E2 ofthe curved guide of the lock E; the lock will rot-ate and thusreestablish the locking. The firing-pin C is maintained in the positionfor firing by the notch D2 of the sear D until it is lifted during thefiring by the trigger (not represented) by the intermedium of the leverN. The firingpin can then move forward freely, the stud C2 slides in therectilinear part E3 of the curved guide of the lock, thus preventing itsbeing unlocked during the firing. The particular disposition of thuerotating lock behind the fore-face of the breech bolt is remarkablydnopposition with the usual disposition of the rotating lock orof themovable breech-head at the fore part of the breech. In order to obtainthe maximum bearing surface of the breech bolt for a minimumdisplacement of the lock, the surface ,of the frame presents alongitudinal groove and a transverse groove. In the first one slides arib M2 of the casingM and serves to reduce the necessary rotation forthe locking; the second one offers at each side of the lock four bearingsurfaces, that is to say in all eight surfaces EA1 (Fig. 9).

When the {ire-arm is to be used as an ordinary repeating arm, z'. c.when the automaticaction of the locking and unlocking of the breech isomitted, use is made of a locking device which keeps the gas piston Bfrom moving from its fore-position notwithstanding the pressure of thegases acting upon it. To this end, a casin O is disposed at the back-endof the breech bolt A. This casing is maintained in the annular groove Af(Fig. 8) by the stud O1, so that the casingO cannot move longitudinally,but can have aA certain rotation. The piston B guided at its back-end inthe casing O has a lug B2 extending upward, which slides in a slotextending the length of the casing and Whose Width is that of the buttonB2. When the casing O is rot-ated by its arm O3 the Width of the slotthe button IB2 of the piston B Will be locked and the piston cannotmove. The breech Will then have to be opened by a handle (notrepresented) after each ,firing to unlock the firing-pin. In thisconstruction as in others, the act-ion of the gases upon the breech andthe locking of the piston could be effected otherwise Without modifyingthe principle of the invention, as for example, by omitting the pistonand by utilizing the firing-pin as a piston.

Without any essential modications of the re-arm, the invention could beused in automatic firing with blank cartridges. To adapt thisinventionto the loW pressure of the gases of these cartridges, the holein the back-end of the cartridge shells is made larger, or more holesare provided. To avoid the penetration of humidity into the cartridgesby the gas-holes at the back-end, they can be stopped up With lac or byother appropriate means.

When it is desired to use ordinary cartridges the fore-part of themechanism is disposed as particularly represented by Fig. 11. The grooveA1 of the former arrangement is omitted. The piston B is extendedforward and penetrates partly in an opening )V1 formed at the back-endof the barrel W. This opening communicates with the opening W throughthe passage I 72. The passage of the gases is regulated by a valve. Theco-ne P of the valvecan occupy three positions: l to close the passageof the gas, when the fire arm is to beused as a repeating lire arm.2..,To give a small passage P1, when the re-arm is to be used for thenormal automatic firing, and 3, to give a Wide passage P2, When the firearm is to be used for the automatic firing With blank cartridges.

l/Vhen the charge has left the cartridgeshell the gases pass through theopening W3 into the passage W2 thence into the opening W1 and there theyact upon the piston B Which can slide in the cylinder of the breech boltA. The action of the piston Will then be the same as that describedabove for the construction' represented by Figs. l to 10.

Having now described my invention, What I claim as new, and desire tosecure by Letters Patent is:

l. In automatic lire-arms with fixed barrels and breech-action, thebreech-action controlled by a lock rotating in a movable breech bolt,the combination of a firing-pin with a rotating lock centered by thecylindrical part of the firing-pin, means by which the firing-pin isdisplaced backward, means by Which the rotating lock is acted upon bythe firing-pin and a sear pivoted to the firing-pin, substantially asdescribed;

2. In automatic fire-arms With fixed barrels and breech-action, thebreech-action controlled by a lock rotating in a movable breech bolt,the combination of a firing-pin with a rotating lock centered by thecylindrical part of the firing pin, ai piston acting upon a jaw of thefiring pin, openings for the gases to reach the fore-end of the piston,means by which thev lock is rotated by a longitudinal movement of thefiring-pin and a sear pivoted to the firing-pin, substantially asdescribed.

3. In automaticre-arms With fixed barrels and breech action, the breechAaction controlled by a lock rotating in a movable breech bolt, thecombination of a firing-'pin with a rotating lock centered by thecylindrical part of the firing-pin, a piston acting upon the firing-pin,an annular groove at the fore-part of the movable breech bolt, a

passage for the gases to reach the fore-end of the piston, means bywhich the lock is rotated by a longitudinal movement of the.

firing-pin and a Sear pivoted to the firingpin, substantially asdescribed.

4. In automatic fire-arms with fixed barJ rels and breech action, thebreech-action controlled by a lock rotating in a movable breech bolt,the combination of a ring-pin with a rotating lock centered by thecylindrical part of the firing-pin, a piston acting upon the firing-pin,openings through which the gases from the barrel at the foreend of thecartridge-shell are led to the foreend of the piston, means' by whichthe lock is rotated by a longitudinal movement of the firing-pin andasear pivoted to the ring pin, substantially as described.

5. In automaticiire-arms with fixed barrels and breech-action, thebreech-action controlled by a lock rotating in a P,movable breech', thecombination of a firing-pin with a rotating lock centered by thecylindrical part of the firing pin, a piston acting upon the firing-pin,openlngs' through which the gases from the barrel at the fore-end of thecartridge-shell are led to the fore-end of the piston, a valveregulating the opening area for the gases led from the barrel to theoreend of the piston, means by which the lock is rotated by alongitudinal movement of the tiring-pin and a sear pivoted to thefiring-pin, substantially as described; 6. In automatic tire-arms withfixed bar. rels and breech-action, the breech-action controlled by alock' rotating in a movable breech bolt, the vcombination of afiring-pm' with a rotating lock centered bythe cylindrical part of thefiring pin, means by which the firing-pin is displaced backward, a studfixed to the firing-pin, a curved groove in the rotating lock, a searwith notches pivoted to the firing-pin, an abutment of the casing forengaging the said seal', substantially'as described.

In testimon whereof I aix my signature in presence o two Witnesses.

KARL AUGUST BRUNING.

